My father just recently bought a F-350 King Ranch 6.0L with 130k Miles. We are having problems starting the truck hot and when we start it cold it starts right up. When its hot the engine cranks and doesn't start. After half an hour to 2 hours it will start right up. The first 2 days after my dad got it it ran great. After that it didn't start after he picked my brother up. So we sent it back to the dealer and he said he "fixed" the IPR valve but we asked for the receipt and it was skeptical. We think its the HPOP but not sure any help is appreciated.

 

What year?

 

If its an 05+ I highly doubt it an HPOP

It sure sounds like an oil internally....

Could be dummy plugs-stand pipes-or possibly the STC fitting

 

Being an 05' ( according to your profile ) I agree its likely dummy plugs, standpipes and or STC fitting. At a bare minimum those items need to be addressed with the updated OEM parts as they are known to cause hot no starts and the STC fitting is known to crack the rear engine cover if allowed to fail, replacement of the rear engine cover is a very expensive repair caused by a 60 dollar part, so I would have it done when the standpipes and dummy plugs are done.

 

Thanks but is there anyway to tell which one it is?

 

Do both sides. No point in just doing in doing one side, for the other to fail probably not long after it.

 

It's possible to apply shop air through the ICP hole on the passenger side oil rail and chase down the leak by listening for escaping air. Commonly referred to as a "high pressure oil system air test". If you plan to try it yourself there are a few more details you need to know.

An OBD monitor (check here if you're not familiar with them https://www.ford-trucks.com/forums/1...eral-info.html) can show the pressure the HPO pump is making and what the PCM is telling the Injector Pressure Regulator (IPR) to do. Good insight into what's going on under the hood.

Another thing to try is unplugging the ICP when it's a hot no-start. This causes the PCM to default a reading for the ICP. If it or the wiring for it is the issue it will start. It's not likely the problem but worth the couple minutes to check, you could get lucky .

Thing is most of these engines had dummy plugs and stand pipes (parts of the HPO system) that just used an o-ring to seal them where they go together. Updated parts have a o-ring with a Teflon backer ring behind it. This keeps the o-rings from squirming around as the pressure fluctuates in the system, the squirming wears the rubber o-rings until they eventually fail completely. the updated parts are (relatively) inexpensive and by the time you get into the engine far enough to change them it's a no-brainier to go back with the updated parts.

The STC fitting connects the the high pressure oil pump to the branch tube fitting where the oil splits to go to each cylinder head. It's important that it line up correctly for a good seal so the "snap" part was used to allow it to swivel as it was bolted down. Problem is the swivel part proved unreliable and often leaks. The new part is a solid piece and comes with an alignment tool in the package to keep it straight for a good seal. Again, no-brainier if you're into the engine that far.

One other point. The ,05 trucks and EX's got the new designed HPO pump but I f your truck has an '04 engine (relatively common for an early build truck) it may have the earlier style HPO pump. If so that may be the issue.